<p>This article discussed the competitive study of thermal radiation, heat source, and hall current effect on MHD (magnetohydrodynamics) nanofluid in three-layer tubes. The motivation stems from the increasing need for efficient thermal energy systems in solar technologies and microfluidic applications. The analysis considers two carbon-based nanofluids, multi-walled and single-walled carbon nanotubes, which are dispersed in a base fluid to enhance thermal performance. The homogeneous nanofluid inside a cylindrical tube 2 has been implemented to analyze the heat and mass transfer rate inside tube 3 from the receiver of the solar heater. The mathematical model based on partial differential equations transformed into the ordinary differential equations were solved by NDSolve command on the Wolfram notebook of "MATHEMATICA" software. The inbuilt command is based on the finite difference method. The key parameters such as Hall current effect, radiation, heat source, Biot number, and magnetic etc., have been incorporated into the physical model to improve the efficiency of the model and study the axial, tangential velocities, and temperature profiles. The results reveal that increasing the rotational parameter enhances the tangential velocity by approximately 15.2% for multi-walled nanotubes and 18.4% for single-walled nanotubes. Similarly, the Hall current parameter increases the peak flow velocity by up to 7.5%. Thermal radiation significantly increases the temperature profile, with a maximum temperature rise of 8.2% when the radiation parameter increases from 0.1 to 0.5. The thermal Biot number shows a substantial effect, where a threefold increase leads to an enhancement of surface temperature by up to 17.6% for single-walled nanotubes. Density diagram shows how the density of a fluid changes from higher density to lower density particles with respect to the various parameters. The findings highlight that multi-walled carbon nanotubes consistently outperform single-walled counterparts in enhancing heat transfer and flow stability. The novelty of this work lies in the comprehensive parametric analysis of combined electromagnetic and thermal effects in a complex three-tube configuration, which has not been fully addressed in previous studies. These insights contribute to the optimized design of high-performance thermal systems for renewable energy, medical sciences and industrial cooling applications.</p>